#include <stdio.h>
#include <assert.h>


size_t mystrlen(const char *str)
{
	assert(str != NULL);
	const char* end = str
	while (*end) {
		end++;
	}
	return end - str;
}

int main()
{
	const char* str = "hello bit!";
	size_t len = mystrlen(str);
	printf("len: %d\n", len);
	return 0;
}